RESUMO
INTRODUCTION: Listeria monocytogenes is the causative agent of listeriosis, a food-borne disease that mainly affects pregnant women, the elderly, and immunocompromised patients. The primary treatment of choice of listeriosis is the combination of ampicillin or penicillin G, with an aminoglycoside, classically gentamicin. The second-choice therapy for patients allergic to ß-lactams is the combination of trimethoprim with a sulfonamide (such as co-trimoxazole). The aim of this study was to analyze the antimicrobial susceptibility profile of strains isolated from human infections and food during the last two decades in Argentina. METHODS: The minimal inhibitory concentration (MIC) of 8 antimicrobial agents was determined for a set of 250 strains of L. monocytogenes isolated in Argentina during the period 1992-2012. Food-borne and human isolates were included in this study. The antibiotics tested were ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, erythromycin, gentamicin, penicillin G, tetracycline and rifampicin. Breakpoints for penicillin G, ampicillin and trimethoprim-sulfamethoxazole were those given in the CLSI for L. monocytogenes. CLSI criteria for staphylococci were applied to the other antimicrobial agents tested. Strains were serotyped by PCR, and confirmed by an agglutination method. RESULTS: Strains recovered from human listeriosis patients showed a prevalence of serotype 4b (71%), with the remaining 29% corresponding to serotype 1/2b. Serotypes among food isolates were distributed as 62% serotype 1/2b and 38% serotype 4b. All antimicrobial agents showed good activity. CONCLUSION: The strains of L. monocytogenes isolated in Argentina over a period of 20 years remain susceptible to antimicrobial agents, and that susceptibility pattern has not changed during this period.
Assuntos
Antibacterianos/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Argentina , Humanos , Listeriose/epidemiologia , Listeriose/microbiologiaRESUMO
Salmonella enterica serovar Heidelberg ranks among the most prevalent causes of human salmonellosis in the United States and Canada, although it has been infrequently reported in South American and European countries. Most Salmonella infections are self-limiting; however, some invasive infections require antimicrobial therapy. In this work we characterized an oxyimino-cephalosporin resistant S. Heidelberg isolate recovered from an inpatient in a Buenos Aires hospital. CMY-2 was responsible for the ß-lactam resistance profile. S. Heidelberg contained a 97kb plasmid belonging to the Inc N group harboring blaCMY-2. ISEcp1 was located upstream blaCMY-2 driving its expression and mobilization. The isolate belonged to sequence type 15 and virotyping revealed the presence of sopE gene. In this study we identified the first CMY-2 producing isolate of S. Heidelberg in Argentina and even in South America.
Assuntos
Proteínas de Bactérias/genética , Fatores R/genética , Infecções por Salmonella/microbiologia , Salmonella enterica/genética , beta-Lactamases/genética , Adulto , Argentina , Elementos de DNA Transponíveis , Gastroenterite/complicações , Gastroenterite/microbiologia , Ordem dos Genes , Genes Bacterianos , Infecções por HIV/complicações , Humanos , Infecções por Salmonella/complicações , Infecções por Salmonella/epidemiologia , Salmonella enterica/classificação , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/enzimologia , Sorotipagem , América do Sul/epidemiologiaRESUMO
OBJECTIVE: To evaluate the capability of 17 national reference laboratories participating in the Latin American Quality Control Program in Bacteriology and Antibiotic Resistance (LA-EQAS) to detect emerging resistance mechanisms- namely: resistance of enterobacteria to carbapenems due to the presence of Klebsiella pneumoniae carbapenemase (KPC) and metallo-beta-lactamase (MBL) type IMP, and intermediate resistance of Staphylococcus aureus isolates to vancomycin (vancomycin-intermediate resistant S. aureus-VISA). METHODS: The following three isolates were sent to the 17 participating LA-EQAS laboratories: KPC -producing Klebsiella pneumoniae PAHO-161, IMP-producing Enterobacter cloacae PAHO-166, and S. aureus PAHO-165 with intermediate resistance to vancomycin. Performance of each of the following operations was evaluated: interpretation of sensitivity tests, detection of the resistance mechanism, and assessment of either inhibition halo size (disk diffusion method) or minimum inhibitory concentration (MIC). RESULTS: Concordance in the detection of resistance mechanisms was 76.4%, 73.3%, and 66.7% for the K. pneumoniae PAHO-161, E. cloacae PAHO-166, and S. aureus PAHO-165 strains, respectively. Concordance between the inhibition areas observed by the participating laboratories and the ranges established by the coordinating laboratory was acceptable for all three isolates, at 90.8%, 92.8%, and 88.9%, respectively. CONCLUSIONS: Overall concordance in on the detection of KPC, MBL, and VISA resistance mechanisms was 72.1%. We consider the national reference laboratories in Latin America capable of recognizing these emerging resistance mechanisms and expect that maximum levels of concordance will be reached in the future.
Assuntos
Proteínas de Bactérias/análise , Resistência Microbiana a Medicamentos/fisiologia , Laboratórios/normas , Ensaio de Proficiência Laboratorial , beta-Lactamases/análise , Resistência Microbiana a Medicamentos/genética , Farmacorresistência Bacteriana Múltipla , Enterobacter cloacae/enzimologia , Klebsiella pneumoniae/enzimologia , Laboratórios/estatística & dados numéricos , América Latina , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas , Testes de Sensibilidade Microbiana/estatística & dados numéricos , Organização Pan-Americana da Saúde , Fenótipo , Controle de Qualidade , Indicadores de Qualidade em Assistência à Saúde , Padrões de Referência , Reprodutibilidade dos Testes , Staphylococcus aureus/enzimologia , Resistência a VancomicinaAssuntos
Infecções Estreptocócicas/microbiologia , Streptococcus suis/isolamento & purificação , Antibacterianos/uso terapêutico , Argentina , Humanos , Masculino , Pessoa de Meia-Idade , Peritonite/diagnóstico , Peritonite/tratamento farmacológico , Peritonite/microbiologia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus suis/classificação , Streptococcus suis/genética , Resultado do TratamentoRESUMO
INTRODUCTION: Streptococcus suis serotype 2 is an important swine pathogen and emerging zoonotic agent causing meningitis and septicemia/septic shock. Strains are usually virulent (Eurasia) or of intermediate/low virulence (North America). Very few data regarding human and swine isolates from South America are available. CASE PRESENTATION: Seventeen new human S. suis cases in Argentina (16 serotype 2 strains and a serotype 5 strain) are reported. Alongside, 14 isolates from pigs are analyzed: 12 from systemic disease, one from lungs and one from tonsils of a healthy animal. All human serotype 2 strains and most swine isolates are sequence type (ST) 1, as determined by multilocus sequence typing and present a mrp+/epf+/sly+ genotype typical of virulent Eurasian ST1 strains. The remaining two strains (recovered from swine lungs and tonsils) are ST28 and possess a mrp+/epf - /sly- genotype typical of low virulence North American strains. Representative human ST1 strains as well as one swine ST28 strain were analyzed by whole-genome sequencing and compared with genomes from GenBank. ST1 strains clustered together with three strains from Vietnam and this cluster is close to another one composed of 11 strains from the United Kingdom. CONCLUSION: Close contact with pigs/pork products, a good surveillance system, and the presence of potentially virulent Eurasian-like serotype 2 strains in Argentina may be an important factor contributing to the higher number of human cases observed. In fact, Argentina is now fifth among Western countries regarding the number of reported human cases after the Netherlands, France, the UK and Poland.
RESUMO
Kocuria rosea is an uncommon pathogen may cause opportunistic infections in immunocompromised patient. We report a HIV patient, who presented bacteremia caused by Kocuria rosea. He was successfully treated with vancomycin and by catheter removal.
Assuntos
Síndrome da Imunodeficiência Adquirida/microbiologia , Bacteriemia/imunologia , Hospedeiro Imunocomprometido , Micrococcaceae/classificação , Micrococcaceae/isolamento & purificação , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-IdadeRESUMO
Salmonellaenterica serovar Heidelberg es uno de los principales agentes causantes de salmonelosis en humanos en Estados Unidos y Canadá, sin embargo, resulta infrecuente en los países de Sudamérica y Europa. En este trabajo se caracterizó un aislamiento de S. Heidelberg resistente a oximino-cefalosporinas recuperado de un paciente internaen un hospital de la Ciudad de Buenos Aires. Se evidenció la presencia de un plásmido de 97 kbperteneciente al grupo de incompatibilidad IncN, portador del gen blaCMY-2. ISEcp1 fue localizado corriente arriba de blaCMY-2, promoviendo su expresión y movilización.El aislamiento de S. Heidelberg correspondió al secuenciotipo 15 y en la virotipifi cación se detectó el gen sopE. En este trabajo describimos por primera vez la producción de CMY-2 en una cepa de S. Heidelberg en nuestro país y América Latina
Salmonellaenterica serovar Heidelberg ranks among the most prevalent causes of human salmonellosis in the United States and Canada, although it has been infrequently reported in South American and European countries.Most Salmonella infections are self-limiting; however, some invasive infections require antimicrobial therapy. In this work we characterized an oxyimino-cephalosporin resistant S. Heidelberg isolate recovered from an inpatient in a Buenos Aires hospital. CMY-2 was responsible for the ß-lactam resistance profi le. S. Heidelberg contained a 97 kb plasmid belonging to the Inc N groupharboring blaCMY-2. ISEcp1 was located upstream blaCMY-2 driving its expression and mobilization.The isolate belonged to sequence type 15 and virotyping revealed the presence of sopE gene. In this study we identifi ed the fi rst CMY-2 producing isolate of S. Heidelberg in Argentina and even in South Americ
Assuntos
Humanos , Masculino , América do Sul/epidemiologia , beta-Lactamases/análise , Salmonella enterica/isolamento & purificação , Plasmídeos/análise , Salmonella enterica/patogenicidadeRESUMO
Kocuria rosea is an uncommon pathogen may cause opportunistic infections in immunocompromised patient. We report a HIV patient, who presented bacteremia caused by Kocuria rosea. He was successfully treated with vancomycin and by catheter removal.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Síndrome da Imunodeficiência Adquirida/microbiologia , Bacteriemia/imunologia , Hospedeiro Imunocomprometido , Micrococcaceae/classificação , Micrococcaceae/isolamento & purificação , Testes de Sensibilidade MicrobianaRESUMO
Molecular typing of the actinomycete Rhodococcus equi is insufficiently developed, and little is known about the epidemiology and transmission of this multihost pathogen. We report a simple, reliable polymerase chain reaction typing system for R. equi based on 3 plasmid gene markers: traA from the conserved conjugal transfer machinery and vapA and vapB, found in 2 different plasmid subpopulations. This "TRAVAP" typing scheme classifies R. equi into 4 categories: traA(+)/vapA(+)B(-), traA(+)/vapA(-)B(+), traA(+)/vapAB(-), and traA(-)/vapAB(-) (plasmidless). A TRAVAP survey of 215 R. equi strains confirmed the strong link between vapA (traA(+)/vapA(+)B(-) plasmids) and horse isolates and revealed other host-related plasmid associations: between traA(+)/vapA(-)B(+) and pigs and between traA(+)/vapAB(-)--a new type of R. equi plasmid--and cattle. Plasmidless strains were more frequent among isolates from nonpathological specimens. All plasmid categories were common in human isolates, which possibly reflects the predominantly opportunistic nature of R. equi infection in this host and a zoonotic origin.
Assuntos
Infecções por Actinomycetales/epidemiologia , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Proteínas de Fímbrias/genética , Glicoproteínas de Membrana/genética , Plasmídeos/genética , Rhodococcus equi/genética , Infecções por Actinomycetales/microbiologia , Animais , DNA Bacteriano/genética , Marcadores Genéticos , Epidemiologia Molecular , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Rhodococcus equi/patogenicidade , VirulênciaRESUMO
Objetivo. Evaluar la capacidad de 17 laboratorios nacionales de referencia que participan en el Programa Latinoamericano de Control de Calidad en Bacteriología y Resistencia a los Antimicrobianos (LA-EQAS) para detectar mecanismos de resistencia emergentes, a saber: resistencia de enterobacterias a carbapenemes por presencia de Klebsiella pneumoniae carbapenemasa (KPC); resistencia de enterobacterias a carbapenemes por presencia de metalobetalactamasas (MBL) tipo IMP, y resistencia intermedia a vancomicina de aislamientos de Staphylococcus aureus (VISA). Métodos. Se enviaron los siguientes tres aislamientos a los 17 laboratorios participantes del LA-EQAS: Klebsiella pneumoniae OPS-161 productor de KPC, Enterobacter cloacae OPS-166 productor de IMP y S. aureus OPS-165 con resistencia intermedia a vancomicina. Se evaluó la interpretación de las pruebas de sensibilidad y detección del mecanismo de resistencia y el tamaño de los halos de inhibición (método de difusión por discos) o valor de la concentración inhibitoria mínima (CIM). Resultados. La concordancia en la detección de los mecanismos de resistencia fue de 76,4%, 73,3% y 66,7% con respecto a la cepas K. pneumoniae OPS-161, E. cloacae OPS-166 y S. aureus OPS-165, respectivamente. La concordancia entre las zonas de inhibición obtenidas por los laboratorios participantes y los rangos establecidos por el laboratorio coordinador fue aceptable en los tres aislamientos, ya que alcanzó 90,8%, 92,8% y 88,9%, respectivamente, para cada cepa. Conclusiones. La concordancia global en la detección de los mecanismos de resistencia KPC, MBL y VISA fue de 72,1%. Consideramos que los laboratorios nacionales de referencia de América Latina son capaces de reconocer estos mecanismos de resistencia emergentes y se espera que en el futuro la concordancia alcance su nivel máximo.
Objective. To evaluate the capability of 17 national reference laboratories participating in the Latin American Quality Control Program in Bacteriology and Antibiotic Resistance (LA-EQAS) to detect emerging resistance mechanisms namely: resistance of enterobacteria to carbapenems due to the presence of Klebsiella pneumoniae carbapenemase (KPC) and metallo-beta-lactamase (MBL) type IMP, and intermediate resistance of Staphylococcus aureus isolates to vancomycin (vancomycinintermediate resistant S. aureusVISA). Methods. The following three isolates were sent to the 17 participating LA-EQAS laboratories: KPC-producing Klebsiella pneumoniae PAHO-161, IMP-producing Enterobacter cloacae PAHO-166, and S. aureus PAHO-165 with intermediate resistance to vancomycin. Performance of each of the following operations was evaluated: interpretation of sensitivity tests, detection of the resistance mechanism, and assessment of either inhibition halo size (disk diffusion method) or minimum inhibitory concentration (MIC). Results. Concordance in the detection of resistance mechanisms was 76.4%, 73.3%, and 66.7% for the K. pneumoniae PAHO-161, E. cloacae PAHO-166, and S. aureus PAHO- 165 strains, respectively. Concordance between the inhibition areas observed by the participating laboratories and the ranges established by the coordinating laboratory was acceptable for all three isolates, at 90.8%, 92.8%, and 88.9%, respectively. Conclusions. Overall concordance in on the detection of KPC, MBL, and VISA resistance mechanisms was 72.1%. We consider the national reference laboratories in Latin America capable of recognizing these emerging resistance mechanisms and expect that maximum levels of concordance will be reached in the future.
Assuntos
Proteínas de Bactérias/análise , Resistência Microbiana a Medicamentos/fisiologia , Laboratórios/normas , Ensaio de Proficiência Laboratorial , beta-Lactamases/análise , Resistência Microbiana a Medicamentos/genética , Farmacorresistência Bacteriana Múltipla , Enterobacter cloacae/enzimologia , Klebsiella pneumoniae/enzimologia , Laboratórios/estatística & dados numéricos , América Latina , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas , Testes de Sensibilidade Microbiana , Organização Pan-Americana da Saúde , Fenótipo , Controle de Qualidade , Indicadores de Qualidade em Assistência à Saúde , Padrões de Referência , Reprodutibilidade dos Testes , Staphylococcus aureus/enzimologia , Resistência a VancomicinaAssuntos
Controle de Qualidade , Resistência Microbiana a Medicamentos , Enterobacteriaceae , Klebsiella pneumoniae , Controle de Medicamentos e Entorpecentes , Ensaio de Proficiência Laboratorial , América Latina , Controle de Qualidade , Resistência Microbiana a Medicamentos , Staphylococcus aureus , Ensaio de Proficiência Laboratorial , América Latina , Proteínas de Bactérias , Resistência Microbiana a Medicamentos , Ensaio de Proficiência Laboratorial , beta-Lactamases , Farmacorresistência Bacteriana Múltipla , Enterobacter cloacae , Fenótipo , Controle de Qualidade , Padrões de Referência , Staphylococcus aureus , Resistência a Vancomicina , Controle de Medicamentos e Entorpecentes , Laboratórios , Testes de Sensibilidade Microbiana , Organização Pan-Americana da Saúde , Indicadores de Qualidade em Assistência à Saúde , Reprodutibilidade dos TestesAssuntos
Humanos , Feminino , Gravidez , Recém-Nascido , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/terapia , Streptococcus agalactiae/patogenicidade , Quimioprevenção , Controle de Infecções/métodos , Hipersensibilidade a Drogas , Doenças do Recém-Nascido , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/prevenção & controle , Infecções Bacterianas/terapia , Fatores de RiscoRESUMO
Thirty-four hemolytic uremic syndrome (HUS) patients and ninety-five family members were studied to determine the frequency of infection with verocytotoxin-producing Escherichia coli (VTEC) in household contacts using three diagnostic criteria: VTEC strains isolation and characterization, detection of free fecal VT (FVT) and VT-neutralizing antibodies (VT-NAbs). Gastrointestinal tract symptoms occurend in one to six family members in 8 (23.5 per cent) of the index cases, the week before admission to hospital or simultaneously. The control group consisted of 34 children with acute gastroenteritis who did not develop HUS. Cumulative evidence of VTEC infection was found in 13 (38.2 per cent) of 34 HUS patients, in 30 (31.6 per cent) of 95 family members and in 10 (29.4 per cent) of 34 control children. The serotypes of VTEC isolated were O157:H7 and O25: H2. The prevalent VT type was VT2 in VTEC and FVT; and VT1 in VT-NAbs. Both parents had the same infection rate by fecal toxin or serological data (11.1 per cent FVT, 32 per cent VT-NAbs). These were higher than those detected in siblings (6.2 per cent FVT, 23.5 per cent VT-NAbs) and grandparents (0 per cent FVT, 18 per cent VT-NAbs). Of 16 patients without evidence of infection, 3 had household contacts with FVT and 13 with VT-NAbs. Our results show the wide dissemination of VTEC in the population of Argentina and that family members of HUS patients are usualy infectd. Therefore, person-to-person transmission may play an important role in the high incidence of HUS in our country.
Assuntos
Humanos , Masculino , Feminino , Lactente , Toxinas Bacterianas/biossíntese , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/diagnóstico , Síndrome Hemolítico-Urêmica/microbiologia , Fezes/microbiologia , Infecções por Escherichia coli/microbiologia , Linhagem , Síndrome Hemolítico-Urêmica/genéticaRESUMO
Se presenta el caso de un niño de 14 meses que desarrolló Sindrome Urémico Hemolítico después de un período prodrómico con vómitos y diarrea mucosanguinolenta del cual se aislaron 2 cepas de E. coli productoras de toxina simil-Shiga (SLT) de diferente serotipo y genotipo. Una de las cepas correspondió al seotipo 0157: H7, biotipo D, productora de SLT II y susceptible a todos los antibióticos probados. Esta cepa hibridizó cona las sondas genéticas para SLT II; la fimbria de adherencia (factor EHEC) y para el factor de fijación y disolución del borde en cepillo ("E. coli attaching and effacing") eae). La otra cepa correspondió al serotipo O25:K2:H2 productora de SLT II en los ensayos de neutralización de efecto citotóxico sobre células VERO utilizando anticuerpos monoclonales, pero negativas para SLT I y SLT II y el factor eae. Sólo fue positiva por hibridización con la sonda para la fimbria de adherencia. Esta cepa presentó además un patron de multiresistencia a los antibióticos probados. Por otra parte, la cepa de E. coli, del serotipo O25: K2: H2 produjo niveles tanto de toxina libre como asociada a células, 20 veces superiores a la cepa del serotipo O157:H7. Esta es la primera publicación de un caso de SUH en el cual se detectó una cepa de E. coli del serotipo O25:H2 produjo niveles tanto de toxina libre como asociada a células, 20 veces superiores a la cepa del serotipo O157:H7. Esta es la primera publicación de un caso de SUH en el cual se detectó una cepa de E. coli del serotipo O25:H2 productora de SLT. Además el hecho de no hibridizar con la sonda genética para SLT II, a pesar de tener una actividad citotóxica neutralizable por el anticuerpo monoclonal (MAb BC5BB12) indicaria que la secuencia que codifica para SLT II no presenta homología con la sonda utilizada. la detección de SLT libre tanto en la materia fecal del niño como en la de su padre (quien padeció diarrea una semana antes), indicaría que el niño adquirió la infección en el entorno familiar